Technical Field
The present disclosure relates to a method for controlling a trip event of an inverter, and more specifically to a method for controlling a trip event of an inverter by taking into account the temperature of the inverter.
Description of the Related Art
An inverter includes circuitry that converts an AC voltage to a DC voltage, switches the converted DC voltage by a switching element according to a pulse width modulation (PWM) signal to generate an AC voltage, and output the generated AC voltage to a load. Such an inverter allows a user to supply an AC voltage having a desirable level and frequency to the load, thereby precisely controlling the load.
In operating an inverter, if an overcurrent flows in the inverter, the temperature of the inverter increases and thus the inverter overheats. If the inverter overheats, a trip event occurs for protecting the inverter. Once a trip event occurs, the inverter is interrupted. There are several ways to control a trip event of an inverter. For example, there is known a latch-type control scheme by which a trip event once occurred due to overheating can be cancelled only by resetting. In addition, there is known a level-type control scheme by which a trip event is automatically cancelled if overheating is gone.
For an inverter using the latch-type control scheme, when a trip event occurs due to overheating, a user has to perform a reset operation by herself/himself. Accordingly, it is necessary to prevent an unnecessary trip event. According to existing trip control schemes, however, it is determined whether a trip event has occurred based on an estimated temperature of the inverter, instead of an actually measured temperature. As a result, it is difficult to accurately control a trip event.